Art of producing silicon monoxid.



imiino STATES m'rnnronnion.

HENRY NOEL POTTER,

OF NEW ROCHELLE, NEW YORK, ASSTGNOR T0 GEO. WESTING-. HOUSE, 01f PITTSBURG,PENNSYLVANIA.

ART OF PRODUCING SILICON MONOXID'.

Specification of Letters Patent.

Patented. nee. e1, 1907.

To all whom 'it may concern:

Be it known that I, HENRY NOEL POTTER, a citizen of the United States, and resident of New Rochelle, county of Westchester, State of New York, have invented certain new and useful Improvements in the Art of Producing Silicon Monoxid, of which the following is a specification.

The process of producing silicon monoxid by heating silicon dioXid to a critical temperature in the presence of carbon is described in my application for Letters Patent of the United States filed December 30, 1904, Serial Number 238,925, the process therein described involving the idea'of removing one oxygen atom from the dioxid of silicon,

thereby producing silicon monoxid. The theory upon which the process rests is that the two atoms of oxygen in SiO molecule, analogously to C0,, are not attached with equal strength and that in reducing the dioxid, one of the oxygen atoms comes off easier than the other, so that there is a tendency to use 'u all the reducing agent by reducin the iO to SiO rather than for some 0 the reducing agent to remove the second oxygen atom, namely that in the SiO, liberating Si.

The present process differs from that de-- scribed in my application mentioned, although it involves a similar theo as to the relative degree of attachment of t e oxygen atoms in the SiO molecule. 1 have found if crystalline metallic silicon is piled about a gra hite core in a vacuum furnace from which the air is partially pumped that onpassing an electric current through the core 1 and heating the same suflici'ently a brown powder having the characteristics of the powder described in my application Number 238,925 is deposited on the wallsof the furnace. This shows that when silicon is oxidized it takes oxygen in two steps, first to SiO, which is the only product that will be formed provided an insufficient quantity of oxygen be present. Presumabl under ideal conditions the Si will wholly c an e to SiO before any of the SiO is oxidized to iO The same result may be obtained by heating the silicon, which is an electrical conductor, by passing a current directly through it so that, instead of surrounding the core with silicon, we can use silicon as the resistance between suitable electrodes composed of car- 1 noxid by keeping the sup ly of oxygen under such ressure and control as is best suited to carrying out the process.

The action on which the successful opera tion of the process ap ears to depend is that silicon be heated in the presence of oxygen under such conditions of oxygen supply and pressure as to prevent the oxidation to the dioxid. This implied an incomplete combustion of silicon as a feature of the process of producing monoxid of silicon. In other Words, to ut the matter in another way, it may be brlefly said that silicon monoxid is in the present process roduced by highly heating silicon in air un er reduced pressure or under conditions which preclude the rapid oxidation which takes place when oxygenis present in large quantities. Under conditions then in which silicon is highly heated in the presence of an atmosphere poor in oxygen, we may produce silicon monoxid. When the silicon thus heated-is in vaporous form the resulting roduct appears in the form of a powder as described in my previous application.

To render the atmosphere in which the heating takes place poor in oxygen, the sup-- I bon or massive silicon, and produce the mo- 2'. The process of producing silicon monoxid, which consists in heating silicon in the presence of oxygen under such conditions of oxygen sup ly as to prevent the oxidation to the dioxi 3. The method of producing silicon inonoxid, which consists in highly heating metallic silicon in. air under reduced pressure. I

4. The method of producing silicon monoxid, which consists in highly heating silicon in an atmosphere poor in oxygen.

5. The method of making a pulverulent compound containing monoxid of silicon, which consists in burning the vapor of silicon witg oxygen insufficient to produce the di- OX1 2. v 1 emcee whic consists in heatmg the vaporof silicon Yor and State of New York, this 9th day of in an atmosphere poor in oxygen. June A. D. 1905.

7. The method of making a pulverulent i HENRY NOEL POTTER. 5 comlilound containing monoxid of silicon, Witnesses: whic consists in high] heating silicon WM. H. CAPEL, v vapor in air under reduce pressure. GEORGE STOOKBRIDGE comyilound containing nionoxid of silicon, f S nedat New Yorl z, in the county of New 

